1. Field of the Invention
The present invention relates to a self-propelled underwater apparatus, commonly called a cleaning robot, designed to function underwater so as to clean the bottom and walls of swimming pools, in particular a robot which is operated electromechanically.
2. Description of the Related Art
These cleaning robots are normally able to perform two separate functions:
on the one hand, suck in the swimming-pool water, pass it through a filtering and, where necessary, disinfecting system, and expel it again; PA1 on the other hand, move along the end wall and, if necessary, along the side walls of the swimming pool, with brush systems which remove the substances deposited on these walls, facilitating suction thereof towards the filtering system. PA1 at least two electric actuating motors contained inside a watertight chamber housed in the body of the robot and connected to an electric power cable passing in a leakproof manner through a hole in the wall of the chamber. This cable is connected up outside the swimming pool and is long enough to follow the movements of the robot along the whole of the swimming pool itself; PA1 a turbine for sucking in and delivering the water through the filtering system, which is rotated by a transmission shaft connected to one of said actuating motors, said shaft passing, in turn, in a leakproof manner through a hole in the wall of the motor housing; PA1 a drive system, of the wheel or belt type, in turn operated by one or two of said actuating motors via an associated transmission shaft and at least one reducer; PA1 a control system, originally of the electric type and currently preferably of the electronic type, for effecting, with appropriate timing, the forwards and backwards movements of the robot and changes in direction. This system is in turn contained inside the watertight chamber of the motor.
The mode of operation of these robots may be of the hydraulic or the electric type: the invention relates to the latter type. The electrically operated cleaning devices which are currently available on the market all have at least the following basic technical characteristics:
These robots have--as can be easily understood since they constantly function underwater--a relatively complex and hence costly liquid-tight structure; in addition, the use of an electronic control board also implies the use of relays and electromagnetic connections which, by their very nature, are costly and delicate; the watertight chamber requires, moreover, the provision of a heat exchanger in order to dispose of the heat generated by the electric and electronic systems contained therein; finally, this watertight chamber, despite all the precautions, is often subject to water-infiltration problems--precisely on account of the environment in which the robot is intended to operate and owing to the fact that the seal between moving parts (fixed housing and rotating shaft) is ensured by a gasket subject to rapid wear--resulting in problems in particular for the electrical parts.